Studies conducted on Arthrobacter species during the past few years indicate that in these organisms, regulation of sugar transport and inducible enzyme synthesis involves several novel features. It is the overall objective of the present research project to elucidate the details of these mechanisms and reactions so that the nature of the regualtion can be better understood. Sugar transport will first be studied in A. pyridinolis. This species has several different systems for sugar transport; the system for fructose transport is a PEP:hexose phosphotransferase while that for glucose does not involve phosphorylation and is dependent upon prior growth on certain Krebs cycle intermediates. Detailed studies will be conducted on these systems, the system for transport of L-rhamnose, and the means whereby they are regulated. Whole cell-studies and isolated membrane preparations will be used. The interaction between the transport systems will be investigated. The inducible transport of glucose in A. crystallopoietes will also be re-examined to determine the mechanism and controls involved. Studies of inducible enzyme synthesis will be pursued primarily in A. atrocyaneus. The inducible beta-galactosidase in this species appears to be subject to a variety of regulatory effects. Investigation of these effects, especially the effect of cyclic AMP, will be continued. In connection with studies of cyclic AMP metabolism in A. atrocyaneus, protein kinase activities in extracts and on the cell "surface" have been found and partially characterized. Further work will be done to characterize these enzymes and to elucidate their physiological substrates and roles.